Microbiology Exam

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Microbiology Exam
2010-04-25 23:36:29
Genetic Engineering

Exam 3
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  1. What is the transformation process?
    • Plasmid (tiny circular DNA) is released from host cell when the cell dies and lyses. The plasmid then is sucked up by another host cell; that cell is now transformed because new genetic information.
    • Ex: if that plasmid carries genes for antibiotic resistance, the transformed cell will be resistant to those antibiotics.
  2. Transduction process?
    The bacteriophage carring the plasmid for the previous host cell, attaches another host cell and injects into the host cell the plasmid (a bacteria or eukaryotic cell). The plasmid combines itself with the chromosome of the host cell.
  3. Conjugation process?
    A F+ cell containg a F plasmid and a cell chromosome; F plasmid has the genes to make F pilus. The F pilus attaches the F+ cell to the F- cell; F pilus shortens making a bridge between the two cells. The plasmid in the F+ begins to replicate, that copy of the F plasmid travels across the bridge to the F- cell and circularizes. Now, both cells have F plasmid bothe are F+, then break apart from each other.
  4. Genetic engineering?
    Involves moving DNA from one cell to another. (one species to another).

    Plasmid (vector) from E. coli is cut by an restriction enzyme, then that same enzyme cuts the target DNA.The plasmid is recombined with the target DNA, sealed with ligase. Finally, transformation is involved by the host cell sucking up the plasmid.
  5. Steps need for genetic engineering?
    • 1. Target DNA
    • DNA which codes for a specific trait or traits; this DNA is eventually moved into a new cell (host cell). Ex. DNA-Human insulin gene
    • 2. Vector or vehicle
    • Helps put target DNA into "host cell."
    • Naked plasmid: into host cell by transformation almost any bacterial cell will take up DNA. Also use viruses (genetically engineering DNA) into host by tranduction; only proper host cell with right receptors can be used.
    • 3. Host cell
    • -Sometimes to receive target DNA; host cell will make proteins that the target DNA codes for.